Details on Facebook 360 Ambisonics Mapping from Angelo Farina

EDIT: You can download a JS effect (for Reaper) that does the conversion from ambiX to TBE and another that goes from TBE to 2nd order, 2D, Furse-Malham format here (I’ve included my remapping JS effect too, so you can also go from Furse-Malham to TBE format by converting to that first 🙂 :

Facebook have updated TBE to remove the ‘R’ component from channel 4. This is important as, before it was removed, it was impossible to go from TBE to 1st order Ambisonics (for Youtube etc.). The new details are excellently discussed on Angelo’s webpage which can be found at http://pcfarina.eng.unipr.it/TBE-conversion.htm

Older Information, pre V2.2 of Facebook Spatial Workstation.

Angelo Farina has published an excellent article detailing how the 9, 2nd order Ambisonic components map to the 8 channels of the Facebook360 TBE format (they decided to pander to the 8-channel limit of pro-tools 🙁 ). All the details can be found at Angelo’s website:

Really useful, as are all your articles and pluging, but would it also be possible to make a TBE to FOA converter to use FOA effects in a TBE project? Using this from the same Farina article:
W = 1.446968601 * TBE(1)
X = 2.047502048 * TBE(3)
Y = -2.047502048 * TBE(2)
U = -1.839587932 * TBE(5)
V = -1.839587932 * TBE(6)

That’d be a TBE to 2nd order, rather than 1st order Ambisonics, but yes, that is straight-forward to implement. What you can’t do is go from TBE to full 2nd order Ambisonics as m=0 channels are combined.

Hi Bruce, very important info.
My formulas for conversion from Ambisonics to TBE were wrong, as I derived them from the behaviour of the Spatialser plugin, which also generates wrong TBE signals, with elevation completely messed up.
I just updated my web page, now it contains the correct formulas. So please, you should fix also this page and your JS plugin!
More info here:https://www.facebook.com/groups/audio360support/permalink/2053591944871670/